466 results on '"Park, Jun-Hee"'
Search Results
202. A Scalable Multicasting with Group Mobility Support in Mobile Ad Hoc Networks
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Kim, Kap-Dong, primary, Lee, Kwang-Il, additional, Park, Jun-Hee, additional, and Kim, Sang-Ha, additional
- Published
- 2007
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203. Design of the Autonomous Fault Processing Mechanism for Home Network
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Son, Young-Sung, primary, Ku, Tai-Yeon, additional, Park, Jun-Hee, additional, and Moon, Kyung-Deok, additional
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- 2007
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204. Hemoptysis after Left Subclavian Central Venous Catheterization during Anesthesia Induction for Open Heart Surgery - Two cases report -
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Do, Jun Yong, primary, Kim, Il Seok, additional, Hong, Sung Jun, additional, Park, Jun Hee, additional, and Shin, Keun Man, additional
- Published
- 2007
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205. The Conversion of a Device And a Control Message in The Universal Middleware Bridge
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Kim, Donghee, primary, Lee, Chang-Eun, additional, Park, Jun Hee, additional, Moon, KyeongDeok, additional, and Lim, Kyungshik, additional
- Published
- 2007
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206. Cervical Transforaminal Axis Measured by MRI and Its Relation to the Internal Jugular Vein, Internal Carotid Artery and Vertebral Artery
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Kang, Sang Soo, primary, Choi, Eun Seon, additional, Park, Jun Hee, additional, Hong, Seong Jun, additional, Kim, Il Seok, additional, Yun, Yeong Jun, additional, and Shin, Keun Man, additional
- Published
- 2007
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207. Distinct Linkage Disequilibrium (LD) Runs of Single Nucleotide Polymorphisms and Microsatellite Markers; Implications for Use of Mixed Marker Haplotypes in LD-based Mapping
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Lee, Kyung-A, primary, Sohn, Kwang-Min, additional, Cho, Seung-Hee, additional, Hwang, Hyokkee, additional, Kim, Sun Woo, additional, Won, Hong-Hee, additional, Kim, Hee-Jin, additional, Kim, Min Ji, additional, Cho, Sang Sun, additional, Park, Jun Hee, additional, and Kim, Jong-Won, additional
- Published
- 2007
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208. The Performance Comparison of the Unicast Routing Protocol and the Broadcast Routing Protocol in the Small-sized Ad hoc Network
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Kim, Dong-Hee, primary, Park, Jun-Hee, additional, Moon, Kyeong-Deok, additional, and Lim, Kyung-Shik, additional
- Published
- 2006
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209. A Study on Hierarchical Overlay Multicast Architecture in Mobile Ad Hoc Networks
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Kim, Kap-Dong, primary, Park, Jun-Hee, additional, Lee, Kwang-Il, additional, Kim, Hag-Young, additional, and Kim, Sang-Ha, additional
- Published
- 2006
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210. Design and Implementation of Cooperation System of UPnP and ACAP
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Kim, Dong-Hee, primary, Park, Dong-Hwan, additional, Park, Jun-Hee, additional, Moon, Kyeong-Deok, additional, and Lim, Kyung-Shik, additional
- Published
- 2006
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211. Home network semantic modeling and reasoning — A case study.
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Pulkkinen, Topi, Sallinen, Mikko, Son, Jiyeon, Park, Jun-Hee, and Lee, Yann-Hang
- Abstract
To use smart home services efficiently, semantic modeling of different layers of home network resources as well as environment data and user's personal data is required. This suggests that a smart home system must be able to support data fusion and derive the context where services are operating in order to classify the new information provided by network agents correctly. Following the recent home network standardization efforts, the paper presents a feasible approach of smart home services and acts as a proof-of-concept for a dynamic home network management and diagnostics system. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
212. Haplotype Structure of the UDP-Glucuronosyltransferase 1A1 (UGT1A1) Gene and Its Relationship to Serum Total Bilirubin Concentration in a Male Korean Population
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Ki, Chang-Seok, primary, Lee, Kyung-A, primary, Lee, Soo-Youn, primary, Kim, Hee-Jin, primary, Cho, Sang Sun, primary, Park, Jun-Hee, primary, Cho, Seunghee, primary, Sohn, Kwang Min, primary, and Kim, Jong-Won, primary
- Published
- 2003
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213. The Effect of Preoperative Pulmonary Arterial Pressure and Right Ventricular Function on the Changes in Right Ventricular Function after Mitral Valve Replacement
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Kang, Sang Hwa, primary, Kwak, Young Lan, additional, Shim, Yon Hee, additional, Oh, Young Jun, additional, Nam, Sang Boem, additional, Park, Jun Hee, additional, and Hong, Yong Woo, additional
- Published
- 2001
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214. Field induced UV-alignment method for a zero pre-tilt liquid crystal cell
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Khoo, Iam Choon, Oh, Seung-Won, Park, Jun-Hee, and Yoon, Tae-Hoon
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- 2016
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215. Usefulness of the melanoma antigen gene (MAGE) in making the differential diagnosis between pleomorphic adenoma and adenoid cystic carcinoma.
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Park, Jun Hee, Yong, Nam, Han, Song Iy, and Lim, Sung-Chul
- Abstract
Objective: The aim of this study was to examine the clinical usefulness of the melanoma antigen gene (MAGE) in making the differential diagnosis between pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC). In addition, using real-time reverse transcriptase polymerase chain reaction (RT-PCR), we examined which melanoma antigen gene was actually expressed in each tumour. Materials and Method: Immunohistochemical staining was performed on samples of paraffin-embedded tissue specimens. Fifty-eight patients were diagnosed as PA (n = 31), ACC (n = 17), and nontumoral salivary tissue (n = 10) using MAGEA and MAGEA4. Using primers that could express MAGEA1, -A2, -A3, -A4, -A6, -A10, and -A12 subtypes, real-time RT-PCR was performed in three cases of PA and four cases of ACC that occurred in fresh tissues. Result: We found no immunohistochemical expression of MAGEA or MAGEA4 in the nontumoral tissue. There was a mild degree of expression with no statistical significance in cases of PA. In ACC, however, in 17 cases (100%) and 16 cases (95%), there was a positive reaction to MAGEA and MAGEA4, respectively. In the RT-PCR analysis, PA showed no MAGE gene expression. However, both MAGEA3 and MAGEA4 were expressed in ACC. Conclusion: These results suggest that MAGE could be used as a biologic marker in the differential diagnosis between PA and ACC. Our results also indicate that the expression of MAGE, as confirmed in the RT-PCR analysis, could be used as an alternative method for the early diagnosis of salivary gland tumours. [ABSTRACT FROM AUTHOR]
- Published
- 2012
216. Simple route to ridge optical waveguide fabricated viacontrolled evaporative self-assembly.
- Author
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Kwon, Soon Woo, Byun, Myunghwan, Yoon, Dae Ho, Park, Jun-Hee, Kim, Woo-Kyung, Lin, Zhiqun, and Yang, Woo Seok
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A simple route to intriguing patterns for optical waveguides was demonstrated by controlled evaporative self-assembly (CESA) of confined microfluid. Silica ridge waveguides were fabricated by applying wet and dry etching based on stripe patterns formed by CESA. The optical mode of the resulting waveguides was confirmed by exposing them to the 1064 nm transmission light. [ABSTRACT FROM AUTHOR]
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- 2011
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217. Investigation on Image Flicker in an FFS-LCD Panel: Dependence on Electrode Spacing.
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Oh, Seung-Won, Park, Jun-Hee, Baek, Jong-Min, Choi, Tae-Hoon, and Yoon, Tae-Hoon
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LIQUID crystal displays ,FLICKER fusion ,FLEXOELECTRICITY - Abstract
In case an LCD panel is driven by a low-frequency fringe field, image flickering phenomenon is detected by the naked human eye. We investigated the dependence on the electrode spacing of the image flickering phenomenon induced by the flexoelectric effect in an FFS LCD panel. We found that the image flicker in an FFS LCD panel under low-frequency driving can be eliminated in a simple manner by optimizing the electrode spacing. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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218. Cold-pressed oil from Citrus aurantifolia inhibits the proliferation of vascular smooth muscle cells via regulation of PI3K/MAPK signaling pathways.
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Song, Byeong-Wook, Lee, Chang Youn, Park, Jun-Hee, Kim, Bomi, Lee, Seahyoung, Lim, Soyeon, Kim, Sang Woo, Choi, Jung-Won, Kang, Misun, Kang, Jung Hwa, Lee, Sung-Suk, Park, Mi-Jin, Moon, Hanbyeol, Hwang, Ki-Chul, and Kim, Il-Kwon
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VASCULAR smooth muscle ,CELLULAR control mechanisms ,MUSCLE cells ,PROLIFERATING cell nuclear antigen ,CELLULAR signal transduction ,CYCLIN-dependent kinases - Abstract
Vascular occlusive disease is a chronic disease with significant morbidity and mortality. Although a variety of therapies and medications have been developed, the likelihood of disease re-emergence is high and this can be life-threatening. Based on a previous screening experiment related to vascular obstructive diseases using 34 types of essential oils, cold-pressed oil (CpO) from Citrus aurantifolia (lime) has been demonstrated to have the best effect for the inhibition of vascular smooth muscle cells (VSMCs) proliferation. The aim of the present study was to evaluate the effect of lime CpO on the pathological changes of VSMCs. To determine this, the effect of lime CpO on VSMC proliferation, a major cause of vascular disease, was investigated. To determine the safe concentration interval for toxicity of CpO during VSMC culture, a dilution of 1x10
-5 was determined using Cell Counting Kit-8 assay, which was confirmed to be non-toxic using a lactate dehydrogenase assay. To examine the effect of lime CpO in cellular signaling pathways, changes in phosphorylation of both the PI3K/AKT/mTOR and extracellular signal-regulated MEK/ERK signaling pathways with serum were investigated. Furthermore, lime CpO with FBS also significantly decreased the expression levels of the cell cycle regulators cyclin D1 and proliferating cell nuclear antigen. Additionally, lime CpO with FBS significantly inhibited the sprouting of VSMCs in an ex vivo culture system. These results suggested that lime CpO inhibited the abnormal proliferation of VSMCs and can be developed as a nature-based therapeutic agent for obstructive vascular disease. [ABSTRACT FROM AUTHOR]- Published
- 2022
219. Intrahepatic adrenocortical adenoma arising from adrenohepatic fusion mimicking hepatic malignancy: Two case reports.
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Cho, Yong Soo, Kim, Jin Woong, Seon, Hyun Ju, Cho, Ju-Yeon, Park, Jun-Hee, Kim, Hyung Joong, Choi, Yoo Duk, Hur, Young Hoe, and NA.
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- 2019
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220. TAK-733 inhibits inflammatory neointimal formation by suppressing proliferation, migration, and inflammation in vitro and in vivo.
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Park, Jun-Hee, Kim, Sang Woo, Cha, Min-Ji, Yoon, Nara, Lee, Chang Youn, Lee, Jiyun, Seo, Hyang-Hee, Shin, Sunhye, Choi, Jung-Won, Lee, Seahyoung, Lim, Soyeon, and Hwang, Ki-Chul
- Published
- 2018
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221. Active monitoring for lifestyle disease patient using data mining of home sensors.
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Son, Young-Sung, Pulkkinen, Topi, and Park, Jun-Hee
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- 2013
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222. Progressive monitoring and treatment planning of diabetes mellitus in smart home environment.
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Pulkkinen, Topi, Son, Young-Sung, Lee, Joohyung, Lee, Yann-Hang, Sallinen, Mikko, and Park, Jun-Hee
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- 2013
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223. Analysis of the rectangular resonator with butterfly MMI coupler using SOI
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Witzigmann, Bernd, Osiński, Marek, Arakawa, Yasuhiko, Kim, Sun-Ho, Park, Jun-Hee, Kim, Eudum, Jeon, Su-Jin, Kim, Ji-Hoon, and Choi, Young-Wan
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- 2018
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224. Analysis on frequency response of trans-impedance amplifier (TIA) for signal-to-noise ratio (SNR) enhancement in optical signal detection system using lock-in amplifier (LIA)
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Eldada, Louay A., Lee, El-Hang, He, Sailing, Kim, Ji-Hoon, Jeon, Su-Jin, Ji, Myung-Gi, Park, Jun-Hee, and Choi, Young-Wan
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- 2017
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225. One-step immunoassay for the detection of food-poisoning related bacteria using a switching peptide.
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Lee, Chang Kyu, Jung, Jaeyong, Kim, Hong-Rae, Bong, Ji-Hong, Kim, Tae-Hun, Park, Jun-Hee, Kwon, Soonil, Kang, Min-Jung, and Pyun, Jae-Chul
- Subjects
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PEPTIDES , *IMMUNOASSAY , *FLUORESCENT dyes , *BACTERIA , *VACCINATION status - Abstract
A one-step immunoassay was developed for five types of food-poisoning-related bacteria using a switching peptide and antibodies isolated from unimmunized horse serum. The one-step immunoassay involves mixing samples and reagents in a homogeneous solution without any washing steps. In this work, a one-step immunoassay configuration was developed using isolated antibodies labelled with an organic fluorescence quencher and a switching-peptide labelled with a fluorescent dye. The fluorescence-labelled switching-peptide was bound to the antigen-binding site of the isolated antibodies before binding to the bacteria (no fluorescence signal), and the switching-peptide dissociated from the antibodies as soon as they bound to the bacteria (fluorescence signal turns on). By quantifying the generated fluorescence signal, the one-step immunoassay presented here allows microbial detection without any washing step. [ABSTRACT FROM AUTHOR]
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- 2022
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226. Elevated risk of end-stage kidney disease in stroke patients: A population-based observational study.
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Chun, Sohyun, Han, Kyungdo, Kim, Bongseong, Lee, Dagyeong, Cho, In Young, Choi, Hea Lim, Park, Jun Hee, Jeon, Junseok, Jang, Hye Ryoun, and Shin, Dong Wook
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CHRONIC kidney failure , *HEMORRHAGIC stroke , *PROPORTIONAL hazards models , *KIDNEY failure , *DISABILITIES - Abstract
Estimating the incidence of end-stage kidney disease (ESKD) in stroke survivors is important to assess and predict clinical course, improve post-stroke quality of life, and ultimately reduce health burden.Our objective was to assess the risk of ESKD in patients compared to a matched stroke-free control cohort.A nationwide retrospective cohort study was conducted in 315,326 stroke subjects and 390,781 matched stroke-free control subjects. Health examination results and claims data were collected from the Korean National Health Insurance Service during 2010–2018. Cox proportional hazard models were used to assess the risk of ESKD in the stroke cohort.During a mean follow-up period of 4.3 years, the incidence of ESKD was 1.83 per 100,000 person-years in the stroke cohort versus 0.57 per 100,000 person-years in the control cohort. The stroke cohort exhibited a significantly higher risk of developing ESKD compared to the matched control, with an adjusted hazard ratio (aHR) of 1.79 (95% confidence interval (CI) = 1.67–1.93). Stroke survivors were associated with a higher risk of developing ESKD, regardless of the severity of disability (aHRs of 1.93, 95% CI = 1.69–2.21 for severe disability; 1.71, 95% CI = 1.41–2.07 for mild disability; and 1.78, 95% CI = 1.65–1.92 for no disability), compared to the matching control cohort. The elevated risk was observed in both hemorrhagic stroke (aHR = 1.96, 95% CI = 1.73–2.23) and ischemic stroke (aHR = 1.75, 95% CI = 1.62–1.89).This study demonstrates that stroke patients have a significantly higher risk of incident ESKD. This highlights the need for heightened clinical awareness and improved monitoring of kidney function in this population. [ABSTRACT FROM AUTHOR]
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- 2024
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227. Role of autophagy in cisplatin-induced ototoxicity.
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Youn, Cha Kyung, Kim, Jun, Park, Jun-Hee, Do, Nam Yong, and Cho, Sung Il
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AUTOPHAGY , *OTOTOXICITY , *CISPLATIN , *DEAFNESS , *CELL death , *IMMUNOFLUORESCENCE - Abstract
Objective Hearing loss is a major side effect of cisplatin chemotherapy. Although cell death in cisplatin-induced ototoxicity is primarily caused by apoptosis, the exact mechanism behind the ototoxic effects of cisplatin is not fully understood. Autophagy is generally known as a pro-survival mechanism that protects cells under starvation or stress conditions. However, recent research has reported that autophagy plays a functional role in cell death also. This study aimed to investigate the role of autophagy in cisplatin-induced ototoxicity in an auditory cell line. Methods Cultured HEI-OC1 cells were exposed to 30 μM cisplatin for 48 h, and cell viability was tested using MTT assays. To evaluate whether autophagy serves to cell death after cisplatin exposure, western blotting and immunofluorescence staining for LC3-II were performed. Markers of two autophagy-related pathways, mTOR and class III PI3K, were also investigated. Results The formation of the autophagic protein LC3-II in response to 30 μM cisplatin increased with time. The early upregulation of autophagy exerted cytoprotective activity via the class III PI3K pathway. But later increase in autophagy induced cell death by suppressing the mTOR pathway. Conclusion Our results prove that autophagy could induce cell death during cisplatin-induced ototoxicity, and modulating the autophagic pathway might be another strategy against cisplatin-induced ototoxicity. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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228. Fluorescence immunoassay of E. coli using anti-lipopolysaccharide antibodies isolated from human serum.
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Bong, Ji-Hong, Kim, Jiyun, Lee, Ga-Yeon, Park, Jun-Hee, Kim, Tae-Hun, Kang, Min-Jung, and Pyun, Jae-Chul
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FLUORESCENCE , *LIPOPOLYSACCHARIDES , *IMMUNOASSAY , *GRAM-negative bacteria , *IMMUNOGLOBULINS , *BLOOD serum analysis - Abstract
Abstract In this work, the gram-negative bacterium Escherichia coli strain BL21(DE3) (with lipopolysaccharide (LPS) in its outer membrane) and its modified ClearColi™ strain (lacking LPS) were used for the separation of anti-LPS antibodies from human serum by the following steps: (1) binding of the serum proteins to BL21(DE3); (2) dissociation of the bound proteins (including anti-LPS antibodies) from BL21(DE3) with acid; (3) filtering of the dissociated proteins using ClearColi to remove unwanted proteins; and (4) separation of the antibody fraction by protein-A column chromatography. The binding properties of the separated antibodies were analyzed by fluorescence-activated cell sorting to confirm their selective binding to LPS on the outer membrane of BL21(DE3), and by thermophoretic immunoassay to estimate their dissociation constant. The in vitro applicability of the separated anti-LPS antibodies was demonstrated through a fluorescence assay of BL21(DE3), after immobilizing the antibodies onto a modified microplate surface. The electrochemical detection of BL21(DE3) was also achieved after immobilizing the anti-LPS antibodies onto a gold electrode. Highlights • Anti-lipopolysaccharide (LPS) antibodies were separated from human serum. • The antibody was separated by using (1) BL21(DE3) and then (2) ClearColi without LPS. • Binding properties of the antibody was analyzed by using FACS and thermophoresis. • Fluorescent and electrochemical immunoassays were demonstrated by using the immobilized antibody. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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229. Longitudinal Effects of Body Mass Index and Self-Esteem on Adjustment From Early to Late Adolescence: A Latent Growth Model.
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YUN, Eun Kyoung, LEE, Hanna, LEE, Ji Uhn, PARK, Jun Hee, NOH, Young Min, SONG, Yu Gil, and PARK, Jung Hwa
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SELF-esteem testing , *BODY mass index , *STATISTICAL significance , *SECONDARY analysis , *CRONBACH'S alpha , *RESEARCH funding , *PSYCHOLOGICAL adaptation , *MULTIVARIATE analysis , *DESCRIPTIVE statistics , *CHI-squared test , *STUDENTS , *QUALITY of life , *STATISTICS , *CLUSTER sampling , *DATA analysis software , *SELF-perception , *ADOLESCENCE - Abstract
Background: Mental and physical development during adolescence is a factor that may affect quality of life in adulthood. Purpose: The aims of this study were to investigate the developmental trajectories of body mass index (BMI), self-esteem, and adjustment among students from early to late adolescence and to examine the longitudinal relationships among these variables. Methods: Data from 2006 to 2012 were collected from the Korean Welfare Panel Study. Of the initial sample of 521 students, 487 completed a validated questionnaire measuring BMI, self-esteem, and adjustment. Latent growth curve modeling analyses were conducted to examine the relationships among the variables. Results: Univariate linear growth models showed a significant increase in BMI and significant declines in both self-esteem and adjustment across three time points from childhood to adolescence. The goodness of fit of the multivariate conditioned model supported the validity of the proposed longitudinal model (comparative fit index =.93, root mean square error of approximation =.08). Change in BMI was significantly linked with change in adjustment (β =.18, p <.05) but not with change in self-esteem, whereas change in self-esteem exerted a statistically significant effect on change in adjustment (β =.47, p <.001). Conclusions/Implications for Practice: Our findings indicate that BMI and self-esteem are key determinants of student adjustment in school settings. Therefore, future health education interventions should focus on enhancing the positive physical and mental self-concepts of students, which should improve health and social behavior among students and subsequently afford a better quality of life for these students in adulthood. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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230. The FaaS system using additive manufacturing for personalized production.
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Kang, Hyoung Seok, Noh, Sang Do, Son, Ji Yeon, Kim, Hyun, Park, Jun Hee, and Lee, Ju Yeon
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THREE-dimensional printing , *PRODUCTION engineering , *ASSEMBLY line methods , *SIMULATION methods & models , *CAD/CAM systems - Abstract
Purpose In this paper, a three-dimensional (3D) printer-based manufacturing line and supporting system, which supports personalized/customized manufacturing for individual businesses or start-up companies, was studied to evaluate the practicality of using additive manufacturing for personalization/mass customization.Design/methodology/approach First, factory-as-a-service (FaaS) system, which provides factory as a service to customers, was proposed and designed to manufacture various products within a distributed manufacturing environment. This system includes 3D printer-based material extrusion processes, vapor machine/computer numerical control machines as post-processes and assembly and inspection processes with an automated material handling robot in the factory. Second, a virtualization module for the FaaS factory was developed using a simulation model interfaced with a cloud-based order and production-planning system and an internet-of-things-based control and monitoring system. This is part of the system for manufacturing operations, which is capable of dynamic scheduling in a distributed manufacturing environment. In addition, simulation-based virtual production was conducted to verify and evaluate the FaaS factory for the target production scenario. Main information of the simulation also has been identified and included in the virtualization module. Finally, the established system was applied in a sample production scenario to evaluate its practicality and efficiency.Findings Additive manufacturing is a reliable, feasible and applicable technology, and it can be a core element in smart manufacturing and the realization of personalization/mass customization.Originality/value Various studies on additive manufacturing have been conducted with regard to replacing the existing manufacturing methods or integrating with them, but these studies mostly focused on materials or types of additive manufacturing, with few advanced or applied studies on the establishment of a new manufacturing environment for personalization/mass customization. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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231. Immunoaffinity biosensors for the detection of SARS-CoV-1 using screened Fv-antibodies from an autodisplayed Fv-antibody library.
- Author
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Jung, Jaeyong, Bong, Ji-Hong, Sung, Jeong Soo, Park, Jun-Hee, Kim, Tae-Hun, Kwon, Soonil, Kang, Min-Jung, Jose, Joachim, and Pyun, Jae-Chul
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SARS virus , *SARS disease , *GREEN fluorescent protein , *AMINO acid sequence , *ESCHERICHIA coli , *BIOSENSORS - Abstract
The detection of severe acute respiratory syndrome coronavirus (SARS-CoV-1) was demonstrated using screened Fv-antibodies for SPR biosensor and impedance spectrometry. The Fv-antibody library was first prepared on the outer membrane of E. coli using autodisplay technology and the Fv-variants (clones) with a specific affinity toward the SARS-CoV-1 spike protein (SP) were screened using magnetic beads immobilized with the SP. Upon screening the Fv-antibody library, two target Fv-variants (clones) with a specific binding affinity toward the SARS-CoV-1 SP were determined and the Fv-antibodies on two clones were named "Anti-SP1" (with CDR3 amino acid sequence: 1GRTTG5NDRPD11Y) and "Anti-SP2" (with CDR3 amino acid sequence: 1CLRQA5GTADD11V). The binding affinities of the two screened Fv-variants (clones) were analyzed using flow cytometry and the binding constants (K D) were estimated to be 80.5 ± 3.6 nM for Anti-SP1 and 45.6 ± 8.9 nM for Anti-SP2 (n = 3). In addition, the Fv-antibody including three CDR regions (CDR1, CDR2, and CDR3) and frame regions (FRs) between the CDR regions was expressed as a fusion protein (Mw. 40.6 kDa) with a green fluorescent protein (GFP) and the K D values of the expressed Fv-antibodies toward the SP estimated to be 15.3 ± 1.5 nM for Anti-SP1 (n = 3) and 16.3 ± 1.7 nM for Anti-SP2 (n = 3). Finally, the expressed Fv-antibodies screened against SARS-CoV-1 SP (Anti-SP1 and Anti-SP2) were applied for the detection of SARS-CoV-1. Consequently, the detection of SARS-CoV-1 was demonstrated to be feasible using the SPR biosensor and impedance spectrometry utilizing the immobilized Fv-antibodies against the SARS-CoV-1 SP. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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232. Scalable long-term extraction of photosynthetic electrons by simple sandwiching of nanoelectrode array with densely-packed algal cell film.
- Author
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Kim, Yong Jae, Yun, JaeHyoung, Kim, Seon Il, Hong, Hyeonaug, Park, Jun-Hee, Pyun, Jae-Chul, and Ryu, WonHyoung
- Subjects
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PHOTOSYNTHESIS , *ALGAL cells , *ELECTROCHEMICAL sensors , *ELECTROLYTIC reduction , *NANOFABRICATION - Abstract
Direct extraction of photosynthetic electrons from the whole photosynthetic cells such as plant cells or algal cells can be highly efficient and sustainable compared to other approaches based on isolated photosynthetic apparatus such as photosystems I, II, and thylakoid membranes. However, insertion of nanoelectrodes (NEs) into individual cells are time-consuming and unsuitable for scale-up processes. We propose simple and efficient insertion of massively-populated NEs into cell films in which algal cells are densely packed in a monolayer. After stacking the cell film over an NE array, gentle pressing of the stack allows a large number of NEs to be inserted into the cells in the cell film. The NE array was fabricated by metal-assisted chemical etching (MAC-etching) followed by additional steps of wet oxidation and oxide etching. The cell film was prepared by mixing highly concentrated algal cells with alginate hydrogel. Photosynthetic currents of up to 106 nA/cm 2 was achieved without aid of mediators, and the photosynthetic function was maintained for 6 days after NE array insertion into algal cells. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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233. Position Error Correction Using Homography in Discretized Positioning Circuit for Gamma-Ray Imaging Detection System.
- Author
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Jeon, Su-Jin, Kim, Jihoon, Ji, Myung-Gi, Park, Jun-Hee, and Choi, Young-Wan
- Subjects
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ELECTROMAGNETIC waves , *ELECTROMAGNETIC theory , *IONIZING radiation , *GAMMA rays , *PHOTOMULTIPLIERS - Abstract
A discretized positioning circuit (DPC) based on a resistive network has been developed to reduce the size of a gamma-ray detection system using multi-anode photomultiplier tubes (MA-PMT) in an array, because it can drastically decrease the number of output channels. The output signal from the gamma-ray detection system is a current pulse generated in each tube that contains information about the gamma-ray energy and detecting position in the array. The output current pulse is distributed to four outputs according to the resistance ratio of the resistive network in the DPC, and the detected position is estimated using the height values of the four distributed current pulses. However, owing to parasitic capacitors of MA-PMT connected in parallel to resistors in the resistive network, the four output pulses are affected by the RC time constants. In particular, when the duration of the input signal is not long enough, the height values of the distributed pulses are reduced, and thereby the position error increases significantly. In this paper, we present a new distortion correction method that considers the pulse duration and the RC time constant. In order to correct the position error, we employed homography, which is a coordinate transformation method. The ideal grid was mapped to a new grid for the distorted position. Using this method, error correction was completely achieved, even for short current pulses. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
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234. MicroRNA-145 suppresses ROS-induced Ca2+ overload of cardiomyocytes by targeting CaMKIIδ.
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Cha, Min-Ji, Jang, Jin-Kyung, Ham, Onju, Song, Byeong-Wook, Lee, Se-Yeon, Lee, Chang Yeon, Park, Jun-Hee, Lee, Jiyun, Seo, Hyang-Hee, Choi, Eunhyun, Jeon, Woo-min, Hwang, Hye Jin, Shin, Hyun-Taek, Choi, Eunmi, and Hwang, Ki-Chul
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MICRORNA , *CALCIUM antagonists , *HEART cells , *GENE targeting , *ENZYME induction , *LUCIFERASES , *GENE expression , *APOPTOSIS - Abstract
Highlights: [•] CaMKIIδ mediates H2O2-induced Ca2+ overload in cardiomyocytes. [•] miR-145 can inhibit Ca2+ overload. [•] A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. [•] Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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235. The promotion of cardiogenic differentiation of hMSCs by targeting epidermal growth factor receptor using microRNA-133a
- Author
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Lee, Se-Yeon, Ham, Onju, Cha, Min-Ji, Song, Byeong-Wook, Choi, Eunmi, Kim, Il-Kwon, Chang, Woochul, Lim, Soyeon, Lee, Chang Youn, Park, Jun-Hee, Lee, Jiyun, Bae, Yoonjin, Seo, Hyang-Hee, Choi, Eunhyun, Jang, Yangsoo, and Hwang, Ki-Chul
- Subjects
- *
HEART development , *CELL differentiation , *MESENCHYMAL stem cells , *EPIDERMAL growth factor receptors , *MICRORNA , *GENE targeting , *CELLULAR therapy , *HEART cells - Abstract
Abstract: Human bone marrow-derived mesenchymal stem cells (hMSCs) are an attractive candidate for cell therapy in heart disease. Low survival and incomplete electromechanical integration between resident cardiomyocytes and transplanted hMSCs remain unsolved. In order for an infarcted heart to tolerate transplantation, differentiation capacity in stem cells must be reinforced. In this study, we found that compound 56, an epidermal growth factor receptor (EGFR) inhibitor, promotes cardiogenic differentiation of hMSCs and the transplantation of hMSCs treated with compound 56 resulted in enhancement of heart functions. Furthermore, hMSCs transfected with microRNA-133a (miR-133a), which targets EGFR, were observed to express cardiac-specific markers. We also discovered that luciferase activity is exclusively decreased by targeting EGFR in hMSCs transfected with miR-133a mimic. These results suggest that EGFR plays a key role in the regulation of cardiogenic differentiation in hMSCs. [Copyright &y& Elsevier]
- Published
- 2013
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236. The role of microRNA-23b in the differentiation of MSC into chondrocyte by targeting protein kinase A signaling
- Author
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Ham, Onju, Song, Byeong-Wook, Lee, Se-Yeon, Choi, Eunmi, Cha, Min-Ji, Lee, Chang Youn, Park, Jun-Hee, Kim, Il-Kwon, Chang, Woochul, Lim, Soyeon, Lee, Chang Hyun, Kim, Soonhag, Jang, Yangsoo, and Hwang, Ki-Chul
- Subjects
- *
MESENCHYMAL stem cell differentiation , *CHONDROGENESIS , *MICRORNA , *CYCLIC-AMP-dependent protein kinase , *REPORTER genes , *CARTILAGE cells , *CELLULAR signal transduction - Abstract
Abstract: Chondrogenic differentiation of mesenchymal stem cells (MSCs) is critical for successful cartilage regeneration. Several methods have been developed to attempt to chondrogenic differentiation, because chondrogenic differentiated cells can form stable cartilage and induce expression of a cartilage-specific phenotype. In this study, we found that both H-89 and microRNA-23b induced differentiation into chondrocyte of hMSCs through down-regulation of protein kinase A (PKA) signaling. The small molecule, H-89, was identified by PCA analysis as a potential mediator of chondrogenic differentiation. H-89 induced the expression of the chondrocyte marker, aggrecan, as well as miR-23b. We searched that miR-23b regulates protein level of PKA. When miR-23b was transfected into hMSCs, chondrogenic differentiation was induced. We confirmed the target of miR-23b using a reporter gene assay. Furthermore, not only H-89 or miR-23b-treated cells, but also cell co-treated with H-89 and miR-23b differentiated into chondrocytes. Our results indicate that H-89 induces the expression of endogenous miR-23b, thereby inducing chondrogenic differentiation by negatively inhibition of PKA signaling. [Copyright &y& Elsevier]
- Published
- 2012
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237. Evaluation of the effects of VKORC1 polymorphisms and haplotypes, CYP2C9 genotypes, and clinical factors on warfarin response in Sudanese patients.
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Shrif, Nassr, Won, Hong-Hee, Lee, Seung-Tae, Park, Jun-Hee, Kim, Ka-Kyung, Kim, Min-Ji, Kim, Seonwoo, Lee, Soo-Youn, Ki, Chang-Seok, Osman, Ihsan, Rhman, Enaam, Ali, Ibtisam, Idris, M., and Kim, Jong-Won
- Subjects
- *
ANALYSIS of variance , *BLOOD coagulation tests , *CHI-squared test , *CONFIDENCE intervals , *DOSE-effect relationship in pharmacology , *EPIDEMIOLOGY , *GENES , *GENETIC polymorphisms , *MASS spectrometry , *HEALTH outcome assessment , *POLYMERASE chain reaction , *RESEARCH funding , *STATISTICS , *T-test (Statistics) , *THROMBOEMBOLISM , *U-statistics , *WARFARIN , *DATA analysis , *MULTIPLE regression analysis , *TREATMENT effectiveness , *DATA analysis software - Abstract
Objective: African populations, including the Sudanese, are underrepresented in warfarin pharmacogenetic studies. We designed a study to determine the associations between the polymorphisms and haplotype structures of CYP2C9 and VKORC1 and warfarin dose response in Sudanese patients, one of the most genetically diverse populations in Africa. Material and methods: The effect of the CYP2C9 polymorphisms ( *2, *3, *5, *6, *8, *9, and *11), 20 VKORC1 tag SNPs and haplotypes, and clinical covariates were comprehensively assessed in 203 Sudanese warfarin-treated patients. Results: Patients with the CYP2C9*2,*5,*6, or *11 variant required a daily warfarin dose that was 21% lower than those with CYP2C9*1/*1 (4.7 vs 5.8 mg/day, P < 0.001). SNPs around the VKORC1 and POL3S genes were divided into two haplotype blocks in Sudanese populations. According to multiple linear regression results, rs8050984, rs7294, and rs7199949 in the VKORC1 and POL3S genes ( P <0.001, <0.001, <0.001, respectively), CYP2C9 genotype ( *2, *5, *6, *11; P < 0.001), body weight ( P = 0.04), target INR ( P = 0.007), and concurrent medications ( P = 0.029) could explain about 36.7% of the total warfarin dose variation. Conclusion: Our data revealed that VKORC1 and CYP2C9 polymorphisms are important factors that influence warfarin dose response in Sudanese patients. Our data suggest that combinations of the SNPs may improve predictions of warfarin dose requirements. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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238. Interleukin 10 polymorphisms differentially influence the risk of gastric cancer in East Asians and Caucasians
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Won, Hong-Hee, Kim, Jong-Won, Kim, Min-Ji, Kim, Seonwoo, Park, Jun-Hee, and Lee, Kyung-A
- Subjects
- *
INTERLEUKIN-10 , *GENETIC polymorphisms , *STOMACH cancer risk factors , *EAST Asians , *CAUCASIAN race , *DISEASE incidence , *HELICOBACTER pylori , *CELL differentiation - Abstract
Abstract: Background: Although a number of association studies of gastric cancer (GC) risk have been conducted worldwide, their results have been inconsistent among different populations. The association between GC incidence and Helicobacter pylori (H. pylori) infection is somewhat of an enigma that has yet to be clearly explained. Geographically-restricted positive selection due to unique environmental pressures often result in large allele frequency differences between populations. Thus, population differences need to be investigated when attempting to identify genes that contribute to phenotypes that differ greatly between populations. Methods: We analyzed population differences in 18 polymorphisms of 12 GC-associated or immune response-related genes from 3 ethnic groups comprising 50 Koreans, 46 Indians, and 60 Caucasians; these groups differed in H. pylori seropositivity and susceptibility to GC. Results: An interleukin 10 (IL10) polymorphism demonstrated a significantly different genotype distribution (F ST =0.306, P =0.014), indicating a large difference between the Korean and Caucasian populations. The odds ratio of IL10 polymorphism allele between the populations was 38.32 (95% confidence interval, 11.49–127.83). Conclusion: This finding, taken together with previous evidence, provides a possible explanation for previous discrepant association results and supports the idea that IL10 gene polymorphisms can differentially affect GC development among populations. [Copyright &y& Elsevier]
- Published
- 2010
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239. Suppressing Pyroptosis Augments Post-Transplant Survival of Stem Cells and Cardiac Function Following Ischemic Injury.
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Lee, Chang Youn, Lee, Seahyoung, Jeong, Seongtae, Lee, Jiyun, Seo, Hyang-Hee, Shin, Sunhye, Park, Jun-Hee, Song, Byeong-Wook, Kim, Il-Kwon, Choi, Jung-Won, Kim, Sang Woo, Han, Gyoonhee, Lim, Soyeon, and Hwang, Ki-Chul
- Subjects
- *
HEART cells , *STEM cells , *CELL physiology , *PYROPTOSIS , *CELL survival , *HEART , *CELL death - Abstract
The acute demise of stem cells following transplantation significantly compromises the efficacy of stem cell-based cell therapeutics for infarcted hearts. As the stem cells transplanted into the damaged heart are readily exposed to the hostile environment, it can be assumed that the acute death of the transplanted stem cells is also inflicted by the same environmental cues that caused massive death of the host cardiac cells. Pyroptosis, a highly inflammatory form of programmed cell death, has been added to the list of important cell death mechanisms in the damaged heart. However, unlike the well-established cell death mechanisms such as necrosis or apoptosis, the exact role and significance of pyroptosis in the acute death of transplanted stem cells have not been explored in depth. In the present study, we found that M1 macrophages mediate the pyroptosis in the ischemia/reperfusion (I/R) injured hearts and identified miRNA-762 as an important regulator of interleukin 1β production and subsequent pyroptosis. Delivery of exogenous miRNA-762 prior to transplantation significantly increased the post-transplant survival of stem cells and also significantly ameliorated cardiac fibrosis and heart functions following I/R injury. Our data strongly suggest that suppressing pyroptosis can be an effective adjuvant strategy to enhance the efficacy of stem cell-based therapeutics for diseased hearts. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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240. Switching-peptides for one-step immunoassay and its application to the diagnosis of human hepatitis B.
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Bong, Ji-Hong, Kim, Hong-Rae, Jung, Jaeyong, Park, Jun-Hee, Sung, Jeong Soo, Lee, Chang Kyu, Choi, Kyung-Hak, Shin, Seong-Shick, Kang, Min-Jung, Kim, Hyun Ok, Lee, Do Young, and Pyun, Jae-Chul
- Subjects
- *
HEPATITIS associated antigen , *IMMUNOASSAY , *HEPATITIS B , *FLUORESCENCE resonance energy transfer , *DIAGNOSIS , *FC receptors - Abstract
Herein, we present switching-peptides for a one-step immunoassay, without the need for additional antibody treatment or washing steps to detect antigen–antibody interactions. Fluorescently labeled switching-peptides were dissociated from the immobilized antibody soon after the antigens were bound to the binding pockets. In this study, four different parts of the antibody (IgG) frame regions were chemically synthesized, and these peptides were bound to immobilized antibodies as switching-peptides. We presented the design principle of switching-peptides and used Pymol software, based on the changes in thermodynamic parameters, to study the interaction between antibodies and switching-peptides. The binding properties of switching-peptides were analyzed based on Förster resonance energy transfer between switching-peptides as well as between switching-peptides and antibodies (IgGs) isolated from different animals. The binding constants of the four switching-peptides to antibodies were estimated to be in the range of 1.48–3.29 μM. Finally, the feasibility of using switching-peptides for the quantitative one-step immunoassay was demonstrated by human hepatitis B surface antigen (hHBsAg) detection and statistical comparison of the assay results with those of conventional ELISA. The limit of detection for HBsAg was determined to be 56 ng/mL, and the dynamic range was estimated to be 136 ng/mL–33 μg/mL. These results demonstrate the feasibility of the one-step immunoassay for HBsAg. • Four kinds of switching-peptides are presented for one-step immunoassay without additional antibody and washing steps. • Switching-peptides bind reversibly to the Fab region of immunoglobulin G and they are released by the binding of antigens. • Affinity constants (K D) of switching peptides to immunoglobulin G was estimated using SPR biosensors. • Detection of human hepatitis B surface antigen (hHBsAg) was demonstrated using switching-peptides. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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241. Demonstration of Q-factor enhancement in a mode splitting-based microdisk-coupled asymmetric Mach–Zehnder interferometer.
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Lee, Tae-Kyeong, Kim, Sun-Ho, Jeon, Su-Jin, Park, Jun-Hee, Kim, Hong-Seung, Kim, Tae-Ryong, Kim, Eudum, Kim, Do-Hyun, and Choi, Young-Wan
- Subjects
- *
INTERFEROMETERS , *RESONANCE - Abstract
We demonstrate significant enhancement of an effective Q-factor in a silica planar waveguide-based asymmetric Mach–Zehnder interferometer (AMZI) coupled with a microdisk. To enhance the Q-factor, which is required to more effectively measure the signal changes occurring during biochemical events, the structure utilizes resonance mode splitting. This phenomenon is observed through power cancellation at the same amplitude and a 180° phase difference of each path in the AMZI. In this study, we experimentally showed the effective Q-factor enhancement by comparing resonance characteristics of a fabricated microdisk, AMZI, and the proposed structure at equal fabrication conditions. We measured an effective Q-factor of 9.15 × 104 with a 22 dB extinction ratio. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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242. Plasma Deposition of Parylene-like Films with Chemical Functional Groups for Immunoassays.
- Author
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Song Z, Jung J, Kim TH, Park JH, Song HW, Kang MJ, Kim MH, and Pyun JC
- Abstract
Parylene-like films obtained via the plasma decomposition of parylene precursors with functional groups (amino and formyl) are proposed as an alternative to those obtained via the thermal method. To analyze the chemical functional groups after plasma deposition, a surface analysis of the parylene films using the two different deposition methods was performed via Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS). The FT-IR analysis revealed that the featured peaks of the chemical functional groups were maintained in the parylene-like films obtained via the plasma deposition method. The XPS analysis revealed that the featured chemical functional groups of parylene-AM and parylene-H were maintained after plasma deposition. The surface energy of the parylene films was estimated by using contact angle measurements. The plasma-deposited parylene films were then employed for protein immobilization via the functional groups using horseradish peroxidase (44 kDa) and green fluorescent protein (25 kDa) as model proteins. The parylene-AM and parylene-H films obtained via plasma deposition exhibited higher immobilization efficiencies than did the same parylene films obtained via thermal deposition. Finally, a competitive immunoassay was obtained by immobilizing the Fv-antibodies on plasma-deposited parylene-AM and parylene-H films via covalent bonding. Using heat-deactivated SARS-CoV-2 as a real sample, the limit of detection at the feasible level for the medical diagnosis of COVID-19 was achieved using a competitive immunoassay based on immobilized Fv-antibodies on plasma-deposited parylene films.
- Published
- 2024
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243. Remote sensing of soil moisture using Rydberg atoms and satellite signals of opportunity.
- Author
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Arumugam D, Park JH, Feyissa B, Bush J, and Mysore Nagaraja SP
- Abstract
Spaceborne radar remote sensing of the earth system is essential to study natural and man-made changes in the ecosystem, water and energy cycles, weather and air quality, sea level, and surface dynamics. A major challenge with current approaches is the lack of broad spectrum tunability due to narrow band microwave electronics, that limit systems to specific science variable retrievals. This results in a significant limitation in studying dynamic coupled earth system processes such as surface and subsurface hydrology from a single compact instrument, where co-located broad spectrum radar remote sensing is needed to sense multiple variables simultaneously or over a short duration. Rydberg atomic sensors are highly sensitive broad-spectrum quantum detectors that can be dynamically tuned to cover micro-to-millimeter waves with no requirement for RF band-specific electronics. Rydberg atomic sensors can use existing transmitted signals such as from navigation and communication satellites to enable remote sensing. We demonstrate remote sensing of soil moisture, an important earth system variable, via ground-based radar reflectometry with Rydberg atomic systems. To do this, we sensitize the atoms to XM satellite radio signals and use signal correlations to demonstrate use of these satellite signals for remote sensing of soil moisture., (© 2024. The Author(s).)
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- 2024
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244. Electrochemical analysis of total phospholipids in human serum for severe sepsis diagnosis.
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Park JH, Song Z, Yun TG, Kim HS, Shin MH, Kang MJ, Park MS, and Pyun JC
- Subjects
- Humans, Prognosis, Biomarkers, Carbon, Phospholipids, Sepsis diagnosis, Sepsis metabolism
- Abstract
Electrochemical analysis of total phospholipids was performed for the diagnosis of sepsis. The influence of electrode materials on the analysis of the chromogenic substrate was analyzed using Au, graphite, and pyrolyzed carbon electrodes. The total phospholipid analysis based on electrochemical analysis with pyrolyzed carbon was used for diagnosis of sepsis using sera from healthy volunteers, systemic inflammatory response syndrome (SIRS), and severe sepsis patients. The analysis results using the optical measurement and the electrochemical analysis were compared for the serum samples from sepsis patients and healthy controls. Additionally, the interference of human serum on the optical measurement and electrochemical analysis was estimated by signal-to-noise (S/N) calculation. The assay results of the levels of other biomarkers for sepsis (C-reactive protein and procalcitonin) and the total phospholipid levels obtained using the optical measurement and electrochemical analysis methods were statistically similar. Finally, the mortality of patients, indicated by the results of the total phospholipid assay performed using the electrochemical analysis of the patient samples collected daily (1, 3, and 7 day(s) after admission to hospital), was compared with the patient mortality assessed via conventional severity indexes, such as the SOFA and APACHE Ⅱ scores. The 28-day survival rate was estimated by Kaplan-Meier survival analysis based on the total phospholipid level of patient samples that were obtained after 1, 3, and 7 day(s) from hospital admission., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2024
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245. Defect-Passivated Photosensor Based on Cesium Lead Bromide (CsPbBr 3 ) Perovskite Quantum Dots for Microbial Detection.
- Author
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Park JH, Kim HR, Kim MJ, Song Z, Kang MJ, Son DH, and Pyun JC
- Abstract
A defect-passivated photosensor based on cesium lead bromide (CsPbBr
3 ) perovskite quantum dots (QD) was fabricated using parylene films, and the photosensor was applied for the microbial detection. The CsPbBr3 perovskite QDs were synthesized to be homogeneous in size under thermodynamic control, and the perovskite QD-based photosensor was fabricated using MoS2 flakes as the electron transfer layer. In this work, a parylene film with functional groups was deposited on a photosensor for physical protection (waterproof) and defect (halide vacancy) passivation of the perovskite QD. As the first effect of the parylene film, the physical protection of the perovskite QD from water was estimated by comparing the photosensor performance after incubation in water. As the second effect of the parylene, the interaction between the functional groups of the parylene film and the halide vacancies of the perovskite QDs was investigated through the bandgap, crystal structure, and trap-state density analysis. Additionally, density functional theory analysis on Mulliken charges, lattice parameters, and Gibbs free energy demonstrated the effect of the defect passivation by parylene films. Finally, the parylene-passivated QD-based photosensor was applied to the detection of two kinds of food-poisoning and gastroduodenal disease bacteria ( Listeria monocytogenes and Helicobacter pylori ).- Published
- 2023
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- View/download PDF
246. A vertically paired electrode for redox cycling and its application to immunoassays.
- Author
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Park JH, Lee GY, Song Z, Bong JH, Kim HR, Kang MJ, and Pyun JC
- Subjects
- Humans, Electrodes, Oxidation-Reduction, Immunoassay, Immunoenzyme Techniques, Computer Simulation
- Abstract
An electrochemical immunoassay based on the redox cycling method was presented using vertically paired electrodes (VPEs), which were fabricated using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as an electrode material and parylene-C as a dielectric layer. For the application to immunoassays, different electrochemical properties of PEDOT:PSS were analyzed for the redox reaction of 3,3',5,5'-tetramethylbenzidine (TMB, the chromogenic substrate for enzyme-immunoassays) at different pH conditions, including the conductivity ( σ ), electron transfer rate constant ( k
app ), and double-layer capacitance ( Cdl ). The influencing factors on the sensitivity of redox cycling based on VPE based on PEDOT:PSS were analyzed for the redox reaction of TMB, such as the electrode gap and number of electrode pairs. Computer simulation was also performed for the redox cycling results based on VPEs, which had limitations in fabrication, such as VPEs with an electrode gap of less than 100 nm and more than five electrode pairs. Finally, the redox cycling based on VPE was applied to the medical diagnosis of human hepatitis-C virus (hHCV) using a commercial ELISA kit. The sensitivity of the redox cycling method for the medical diagnosis of hHCV was compared with conventional assay methods, such as TMB-based chromogenic detection, luminol-based chemiluminescence assay, and a rapid test kit (lateral flow immunoassay).- Published
- 2023
- Full Text
- View/download PDF
247. Enhanced anti-tumor immunity of vaccine combined with anti-PD-1 antibody in a murine bladder cancer model.
- Author
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Lim S, Park JH, and Chang H
- Subjects
- Animals, Mice, Cell Line, Tumor, Mice, Inbred C3H, Tumor Microenvironment, Immunoglobulin G therapeutic use, Urinary Bladder Neoplasms therapy, Cancer Vaccines
- Abstract
Purpose: Programmed cell death protein 1 (PD-1) and ligand programmed death ligand 1 (PD-L1) are important immune-suppressive regulators in the tumor microenvironment. A vaccine-induced immune effect on tumor cells is blunted by the immunosuppressive tumor microenvironment. Therefore, we hypothesized that a dendritic cell (DC) vaccine combined with anti-PD-1 (αPD-1) antibodies could elicit a synergistic anti-tumor immunity in bladder cancer., Materials and Methods: We produced a model of subcutaneous transplantation in C3H/HeJ mice by transplanting murine MBT-2 bladder cancer cells. DCs were isolated from normal C3H/HeJ mice, followed by stimulation against MBT-2 lysate before injection. Two weeks later of MBT-2 inoculation, αPD-1 and stimulated DCs were injected two times at one-week interval intraperitoneally and intravenously, respectively. Tumor-infiltrating immune cells and splenocytes were analyzed using flow cytometry. T-cell-mediated anti-tumor responses were measured by interferon (IFN)-γ ELISPOT and lactate dehydrogenase assays., Results: The mice treated with DC+αPD-1 showed a significant decrease in tumor volume compared to the DC-treated mice and IgG-treated group. Survival of the DC+αPD-1-treated group was improved compared with that of the IgG-treated mice. IFN-γ secretion from splenocytes against tumor cells was significantly increased in the DC+αPD-1 group compared with that of αPD-1-treated mice. The frequency of CD8
+ and CD4+ T-cells in spleens was statistically increased in the DC+αPD-1-treated mice compared to those receiving monotherapy (DC- or αPD-1-treated group)., Conclusions: Our results support the hypothesis that the combination therapy of a DC vaccine and αPD-1 antibodies could enhance the anti-tumor immune response against bladder cancer., Competing Interests: The authors have nothing to disclose., (© The Korean Urological Association.)- Published
- 2023
- Full Text
- View/download PDF
248. Carbon electrode obtained via pyrolysis of plasma-deposited parylene-C for electrochemical immunoassays.
- Author
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Song Z, Park JH, Kim HR, Lee GY, Kang MJ, Kim MH, and Pyun JC
- Subjects
- Electrodes, Humans, Immunoassay, Polymers, Xylenes, Carbon chemistry, Pyrolysis
- Abstract
In this study, parylene-C films from plasma deposition as well as thermal deposition were pyrolyzed to prepare a carbon electrode for application in electrochemical immunoassays. Plasma deposition could prepare parylene-C in a faster deposition rate and more precise control over the thickness in comparison with the conventional thermal deposition. To analyze the influence of the deposition method, the crystal and electronic structures of the pyrolyzed parylene-C films obtained via both deposition methods were compared using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. For application as a carbon electrode in immunoassays, the electrochemical properties of the pyrolyzed carbon films from two both deposition methods were analyzed, including the double layer capacitance (2.10 μF cm
-2 for plasma deposition and 2.20 μF cm-2 for thermal deposition), the apparent electron transfer rate (approximately 1.1 × 10-3 cm s-1 for both methods), and the electrochemical window (approximately -1.0 ∼ 2.1 V for both methods). Finally, the applicability of the pyrolyzed carbon electrode from parylene-C was demonstrated for the diagnosis of human hepatitis-C using various amperometric methods, such as cyclic voltammetry, chronoamperometry, square-wave voltammetry and differential pulse voltammetry.- Published
- 2022
- Full Text
- View/download PDF
249. Capacitive biosensor based on vertically paired electrodes for the detection of SARS-CoV-2.
- Author
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Park JH, Lee GY, Song Z, Bong JH, Chang YW, Cho S, Kang MJ, and Pyun JC
- Subjects
- Computer Simulation, Electrodes, Humans, SARS-CoV-2, Sensitivity and Specificity, Biosensing Techniques methods, COVID-19
- Abstract
Vertically paired electrodes (VPEs) with multiple electrode pairs were developed for the enhancement of capacitive measurements by optimizing the electrode gap and number of electrode pairs. The electrode was fabricated using a conductive polymer layer of PEDOT:PSS instead of Ag and Pt metal electrodes to increase the VPE fabrication yield because the PEDOT:PSS layer could be effectively etched using a reactive dry etching process. In this study, sensitivity enhancement was realized by decreasing the electrode gap and increasing the number of VPE electrode pairs. Such an increase in sensitivity according to the electrode gap and the number of electrode pairs was estimated using a model analyte for an immunoassay. Additionally, a computer simulation was performed using VPEs with different electrode gaps and numbers of VPE electrode pairs. Finally, VPEs with multiple electrode pairs were applied for SARS-CoV-2 nucleoprotein (NP) detection. The capacitive biosensor based on the VPE with immobilized anti-SARS-CoV-2 NP was applied for the specific detection of SARS-CoV-2 in viral cultures. Using viral cultures of SARS-CoV-2, SARS-CoV, MERS-CoV, and CoV-strain 229E, the limit of detection (LOD) was estimated to satisfy the cutoff value (dilution factor of 1/800) for the medical diagnosis of COVID-19, and the assay results from the capacitive biosensor were compared with commercial rapid kit based on a lateral flow immunoassay., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
250. Electrochemical One-Step Immunoassay Based on Switching Peptides and Pyrolyzed Carbon Electrodes.
- Author
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Park JH, Song Z, Bong JH, Kim HR, Kim MJ, Choi KH, Shin SS, Kang MJ, Lee DY, and Pyun JC
- Subjects
- Animals, Electrodes, Immunoassay, Immunoglobulin G, Carbon chemistry, Peptides
- Abstract
Switching peptides were designed to bind reversibly to the binding pocket of antibodies (IgG) by interacting with frame regions (FRs). These peptides can be quantitatively released when antigens bind to IgG. As FRs have conserved amino acid sequences, switching peptides can be used as antibodies for different antigens and different source animals. In this study, an electrochemical one-step immunoassay was conducted using switching peptides labeled with ferrocene for the quantitative measurement of analytes. For the effective amperometry of the switching peptides labeled with ferrocene, a pyrolyzed carbon electrode was prepared by pyrolysis of the parylene-C film. The feasibility of the pyrolyzed carbon electrode for the electrochemical one-step immunoassay was determined by analyzing its electrochemical properties, such as its low double-layer capacitance ( C
dl ), high electron transfer rate ( kapp ), and wide electrochemical window. In addition, the factors influencing the amperometry of switching peptides labeled with ferrocene were analyzed according to the hydrodynamic radius, the number of intrahydrogen bonds, dipole moments, and diffusion coefficients. Finally, the applicability of the electrochemical one-step immunoassay for the medical diagnosis of the human hepatitis B surface antigen (hHBsAg) was assessed.- Published
- 2022
- Full Text
- View/download PDF
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